jitcode act relu, exp, sigmoid, tanh

* fix space_to_depth_op unicode problem

* test=develop

change the target cost of test_label_semantic_roles to speed up test

* Fix truncated normal.

* Fix.

* Make nce support more distribution.

* Fix API.spec.

* Fix python API.

* Fix.
test=develop

* Fix API.spec
test=develop

* Fix sampler.

* Fix order of arguments in python API.
test=develop

test=develop

test=develop

Add PRelu tensorRT plugin and Conv2d transpose op converter

Fix expand op incorrect infer shape

* add cudnn ctc loss

* wip add test test=develop

* wip

* wip

* done test=develop

* move include cudnn test=develop

* test test=develop

* fix build test=develop

* fix build test=develop

* fix build on cudnn5 test=develop

* fix cudnn5 build test=develop

* fix cudnn5 build test=develop

* merge develop softmax functor change test=develop

test=develop

test=develop

fix typo test=develop

adjust the python script

* fix inference on gpu out of mem

the transfer logic in operator.cc will keep creating new scopes.

* rename and fix blas vsqr

test=develop

* update

test=develop

test=develop

test=develop

test=develop

* add is_test to pooling and activations

add prop_kind support for layers activation. conv and pooling

add a pass that sets is_test to true

add transpiler version of is_test pass

test=develop

* patch test and pass

test=develop

* add pass to analyzer.h

test=develop

* add is_test attr description & pass only on mkldnn

in:
activation_op.cc
batch_norm_op.cc
conv_op.cc
dropout_op.cc
lrn_op.cc
pool_op.cc
sequence_pool_op.cc
softmax_op.cc

* fix is_test handling for activation pool and conv

* change description of is_test for all layers again

* remove GetAttr(use_mkldnn) from pass

* rename correct_mkldnn_test_phase to is_test

and remove dependency on MKLDNN
test=develop

* review fix magic number

* two if(..)s into one

* Check is_test once and pass mkldnn forward prop kind

* dereference shared_ptr with * (without get())

test=develop

* add is_test_pass back

test=develop

* add selu

* use for range
test=develop

* add API
test=develop

* follow comment
test=develop

* update API.spec
test=develop

add test_analyzer_mobilenet

test=develop

test=develop